http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \#; -C<[b
} (S[" ak
for(int i=0;i<nEndPos.length-1;i++) r*!sA5
{ T7{Z0-
nEndPos = nStartPos[i+1]; .<C}/Cl
} :LwNOuavN
nEndPos[nEndPos.length-1] = nFileLength; h[0,/`qb{
} GKNH{|B$D
} l[q%1-N
$Z;?d@6yI
dM1)wkbET
//启动子线程 R1DXi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U{2UKD@PM
for(int i=0;i<nStartPos.length;i++) k~st;FO
{ ,Si23S\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OO:^#Mvv5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e)~7pXYV)
nStartPos,nEndPos,i); t%n3~i4X:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [fU2$(mT+
fileSplitterFetch.start(); D{aN_0mT
} IP`;hC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N+9`'n^x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1cyX9X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G,8LF/sR
nEndPos = " + nFileLength); Jyx6{Oj
// fileSplitterFetch[nPos.length-1].start(); 4#z@B1Jx
,afh]#
uYPdmrPB?l
//等待子线程结束 8h#/b1\
//int count = 0; qxsK-8KT<
//是否结束while循环 Jk)^6
boolean breakWhile = false; $#dPM*E
q=5#t~?
+FWkhmTv
while(!bStop) 4 }l,F
{ r2T-=XWB
write_nPos(); i[~oMwc&
Utility.sleep(500); b0CtQe
breakWhile = true; zhDmZ
hY.zwotH
u$N2uFc
for(int i=0;i<nStartPos.length;i++) c%aY6dQG&%
{ $^Dx4:k<2
if(!fileSplitterFetch.bDownOver) 3+;}2x0-F
{ pNo<:p
breakWhile = false; 05\A7.iy
break; vmW4 3K;
} h,q%MZ==^s
} <aR8fU
if(breakWhile) ;K:)R_H
break; >Rw[x
f!~gfnn
i51~/ R
//count++; &P%3'c}G
//if(count>4) h'x|yy]@3
// siteStop(); Ch`XwLY9
} ;(Q4x"?I
`/'Hq9$F<"
5A:mu+Iz6H
System.err.println("文件下载结束！"); iNR6BP W
} 5uK:f\y)l
catch(Exception e){e.printStackTrace ();} {|%N
} %v\0Dm+A
;%Jw9G\h
U3 e3
//获得文件长度 *f:^6h
public long getFileSize() bmotR8d
{ M$z.S0"
int nFileLength = -1; &j,rq?eh$
try{ _yyQ^M/
URL url = new URL(siteInfoBean.getSSiteURL()); Gw*n,*pz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0+0+%#?
httpConnection.setRequestProperty("User-Agent","NetFox"); e g#.f`
u0^: XwZ!
q"5iza__H
int responseCode=httpConnection.getResponseCode(); |~bl%g8xP
if(responseCode>=400) E ?(
{ pq6}q($Rk
processErrorCode(responseCode); KDW%*%!
return -2; //-2 represent access is error s#ijpc>h
} 9cAb\5c|
=N`"%T@=
c~(+#a
String sHeader; 3~\mP\/4v
\iAkF`OC
EZz Ox(g
for(int i=1;;i++) @<e+E"6
{ aE6I|6W?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NaSgK
//Utility.log(in.readLine()); f0fN1
sHeader=httpConnection.getHeaderFieldKey(i); Au$|@
if(sHeader!=null) Ql>DS~a
{ &}S#6|[i
if(sHeader.equals("Content-Length")) {Q[{H'Oa
{ I|JMkP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zg&<HJO
break; _|xO4{X
} 4G&E?
} Cs7YD~,
else 6~sb8pK.=
break; q_5k2'4K
} 716JnG>
} t5#IiPp
catch(IOException e){e.printStackTrace ();} o`HZS|>K*
catch(Exception e){e.printStackTrace ();} IpmblC4
>v@R]9
@gQ{*dN
Utility.log(nFileLength); }.Ht=E]
|jV>
V2cLwQ'0
return nFileLength; :3$WY<
} .oYUA}
rIg1]q
rG1l:Z)
//保存下载信息（文件指针位置） Y@N}XH<4R
private void write_nPos() (7q!Z!2
{ ;wIpche
try{ FyX\S=
output = new DataOutputStream(new FileOutputStream(tmpFile)); m(E-?VMHo
output.writeInt(nStartPos.length); f( 5c
for(int i=0;i<nStartPos.length;i++) ps"DL4*
{ Ln0rm9FV-
// output.writeLong(nPos); Y~vI@$<~(
output.writeLong(fileSplitterFetch.nStartPos); CN@bJo2
output.writeLong(fileSplitterFetch.nEndPos); M ()&GlNs
} cj@Ygc)n
output.close(); LFob1HH*8
} 9D++SU2:}
catch(IOException e){e.printStackTrace ();} *{8Kb>D
catch(Exception e){e.printStackTrace ();} Eym<DPu$n
} L8N`<a5T
6+(g4MW
@FKNB.>
//读取保存的下载信息（文件指针位置） +M!f}=H
private void read_nPos() `me2Q
{ r k;k:<c
try{ "tB"C6b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BB5(=n+
int nCount = input.readInt(); Tw"u{%t
nStartPos = new long[nCount]; 9nlfb~F~P
nEndPos = new long[nCount]; * F%Wf
for(int i=0;i<nStartPos.length;i++) EV| 6._Z(D
{ b;#3X)
nStartPos = input.readLong(); wl #Bv,xf
nEndPos = input.readLong(); ^AtAfVJN0
} :zZK%}G<
input.close(); ]7n+|@3x
} 2`I" QU
catch(IOException e){e.printStackTrace ();} 5*u0VabC<
catch(Exception e){e.printStackTrace ();} +uKh]RP
} 2Jl6Xc8
x?Doe`/6?
Aa-L<wZVPt
private void processErrorCode(int nErrorCode) fOCLN$x^
{ jIwz G+)$P
System.err.println("Error Code : " + nErrorCode); 0P^RciC f
} (:Rj:8{
AJt*48H*G
I}Uj"m`>
//停止文件下载 ED&>~~k)
public void siteStop() m07= _4
{ yKF"\^`@
bStop = true; X&fM36o7
for(int i=0;i<nStartPos.length;i++) Z`<S_PPz
fileSplitterFetch.splitterStop(); r$}M,! J
NrT!&>M
&p=Uus
} 1@sy:{ d`
} T%Xl(.Ft
//负责部分文件的抓取 _0ki19rs
**FileSplitterFetch.java V @8+
*/ 3maiBAOKz
package NetFox; UXwnE@`F
mH2XwA|
G=Hvh=K(
import java.io.*; OAO|HH
import java.net.*; FIhq>L.q4
t?f2*N:
+X(@o
public class FileSplitterFetch extends Thread { U/9xO"b{.
:UM>`Y
d\dh"/_$
String sURL; //File URL WG>Nm89
long nStartPos; //File Snippet Start Position lYldq)qB{
long nEndPos; //File Snippet End Position "vI:B}
int nThreadID; //Thread's ID m/uBM6SXx
boolean bDownOver = false; //Downing is over *Z\B9mx
boolean bStop = false; //Stop identical U8Z(=*Z3
FileAccessI fileAccessI = null; //File Access interface .1<QB{4~v
P}hHx<L
t=o2:p6&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &7_xr.c7
{ / r6^]grg
this.sURL = sURL; #&<>|m
this.nStartPos = nStart; <y[LdB/a
this.nEndPos = nEnd; 4\ R2\
nThreadID = id; z5`AJrj%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *Z'*^Y1le
} V .+ mK|)
4H'\nsM
x9Um4!/t
public void run() @-=0T!/
{ ?D?_D,"C
while(nStartPos < nEndPos && !bStop) c-1,((p
{ OQ>8Q`
:bt;DJ@
Em8q1P$tm>
try{ vOIK6-
URL url = new URL(sURL); A) {q7WI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4.Luy
httpConnection.setRequestProperty("User-Agent","NetFox"); -{[5P!
String sProperty = "bytes="+nStartPos+"-"; .kKU MyW(
httpConnection.setRequestProperty("RANGE",sProperty); r Q)?Bhf
Utility.log(sProperty); ZLm?8g6-
:"QR;O@
yu3: Hv}
InputStream input = httpConnection.getInputStream(); 7[=*#7}.
//logResponseHead(httpConnection); e$kBpG"D
c"HB7
`o|Y5wQ@
byte[] b = new byte[1024]; <% #Dwo}
int nRead; <&JK5$l<X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e=uElp'%
{ G*;?&;*
nStartPos += fileAccessI.write(b,0,nRead); xE>H:YPm
//if(nThreadID == 1) zv[$N,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L_4c~4
} xAJ N(8?
\tR](, /
0Va+l)F
Utility.log("Thread " + nThreadID + " is over!"); 24{Tl q3
bDownOver = true; o>4mkh[3
//nPos = fileAccessI.write (b,0,nRead); 3XykIj1
} b0X<)1O
catch(Exception e){e.printStackTrace ();} |T`ZK?B+u
} VZveNz@]r
} P;~`%,+S
YkWv*l
T0HNld
//打印回应的头信息 Oly"ll*K
public void logResponseHead(HttpURLConnection con) @6["A'h
{ >qE f991SZ
for(int i=1;;i++) .,({&L
{ H){}28dX
String header=con.getHeaderFieldKey(i); AS1#_fC
if(header!=null) M~/Pk7CC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1`6kc9f.
Utility.log(header+" : "+con.getHeaderField(header)); |:7 ^
else -d-vzri
break; h2S!<
} FS'|e?WU
} TEJn;D<1I,
8U8%XIEJ
,5*Z<[*
public void splitterStop() 1s-dqHz"s
{ 8NF93tqD6
bStop = true; lL\%eQ
} srbES6
7Gh+EJJ3I
nu(;yIRP
} QT8GP?F
()}(3>O-
X&LaAqlSG
/* Bm>>-nG;
**FileAccess.java 6 4,('+
*//文件访问(定位，写) a^vTBJXo
package NetFox; CE5A^,EsB
import java.io.*; NZb}n`:
omP\qOc
r5,V-5b
public class FileAccessI implements Serializable{ ?td`*n~,
n[KLY!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ApD`i+Y@
RandomAccessFile oSavedFile; :kMF.9U:
long nPos; Rs@>LA
1agNwFd~
8@ZZ[9kt
public FileAccessI() throws IOException mOC<a7#
{ 79*f <Gr
this("",0); [%c5MQ?H
} @fQvAok
XN^l*Q?3n
Q]{`m
public FileAccessI(String sName,long nPos) throws IOException ^7Rc\
{ BHu%x|d
oSavedFile = new RandomAccessFile(sName,"rw"); 41v#|%\w
this.nPos = nPos; a.z)m}+
oSavedFile.seek(nPos); 5La' I7q
} [C#H _y(
4{QD: D(D
OZR{+YrB^
public synchronized int write(byte[] b,int nStart,int nLen) gy`WBg(7x
{ ["_+~*
int n = -1; <nk9IAH
try{ 4%$#
oSavedFile.write(b,nStart,nLen); F{G.dXZZ<
n = nLen; 0z$::p$%u
} 4aiI&,
catch(IOException e) %M*2j%6
{ 2EH0d6nt
e.printStackTrace (); 7'!DK;=TD6
} sj3[ny;b
$DlO<
y 2C Jk~
return n; h e[2,
} udOdXz6K?
{O6yJckH
Ys0N+
} K|Xr~\=
$x*(D|\'<
CjGQ
/* (DkfLadB
**SiteInfoBean.java !C@+CZXLx
*/ $-p9cyk
package NetFox; ^GS\(egt
u]OYu
fXe$Ug|5a
public class SiteInfoBean { sDB,+1"Y$
R2A#2{+H
\30rF]F`l
private String sSiteURL; //Site's URL >QdT7gB
private String sFilePath; //Saved File's Path 8},:
private String sFileName; //Saved File's Name P*]hXm85[K
private int nSplitter; //Count of Splited Downloading File "QvTn=
&I:ZJuQ4
^ib =fLu
public SiteInfoBean() uD?Rs`
{//nSplitter的缺省值为5 R;zf x/
//default value of nSplitter is 5 IgN^~ag`
this("","","",5); &O5O@3:7]
} J$U_/b.mk
Us.k,
w*]FJ-b<.j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {rwT4]4
{ "yc|ng
sSiteURL= sURL; ,n2"N5{jw
sFilePath = sPath; 4y.qtiIP>$
sFileName = sName; DkSs^ym
this.nSplitter = nSpiltter; 4peRbm
V%B~ q`4
dQz#&&s-
} gT(8.<h8
"|Kag|(qB
<kk!nsI
public String getSSiteURL() pfs]pDjS:
{ EywBT
return sSiteURL; .K]Uk/W
} ROXa/
^]D+H9Tl
PuhvJHT
public void setSSiteURL(String value) !b=W>5h
{ gWL`J=DiU
sSiteURL = value; >=:^N-a
} i{16&4 '
H@u5&
LIrebz
public String getSFilePath() a`[9<AM1#
{ UZs'H"K
return sFilePath; ! ,0
} [RF]lM]w
Wffz&pR8
Abi(1nXdQ
public void setSFilePath(String value) $}'(%\7"
{ #G_'5{V
sFilePath = value; nW} s
} M%Ksyr9
.lq83; k
oh@Ha?
public String getSFileName() `/?'^A%Ik
{ 7A) E4f'
return sFileName; 3Fxr=
} ##}7cFX
awI{%u_(nA
}'faf{W
public void setSFileName(String value) `23][V
{ 74a@/'WbE
sFileName = value; NuOxEyC
} Vh>cV
fUGappb
Dx`-h#
public int getNSplitter() OScqf]H
{ 0~K&P#iR
return nSplitter; =Xg/[J%
} e(xuy'4r
3Pllxq<n
)TKn5[<4
public void setNSplitter(int nCount) fm`V2'Rm
{ E4>}O;m0
nSplitter = nCount; O`@- b#
} Goc?HR
} tXH;4K@
H17I"5N
AS@(]T#R
/* \@WVeFr
**Utility.java <nN.$4~X
*/ 5 7t.Ud
package NetFox; Z/:F)c,x
=>B"j`oR
o5 fV,BJZO
public class Utility { C}pm>(F~
V-@4s}zX
6%ofS8[
public Utility() ZQ+DAX*MS
{ |bnYHP$!
<Q/)SN6_E
~/9RSdv7
} vdAd@Z~\
#IZh}*$
//线程睡眠 Vub6wb<G[
public static void sleep(int nSecond) :;yrYAyT3
{ LUId<We
try{ [M,4qe8,}
Thread.sleep(nSecond); )J> dGIb
} iiMS3ueF
catch(Exception e) U|xHy+N
{ ThgJ '
e.printStackTrace (); 5;HGS{`
} Fd\uTxykp
} GT6i9*tb#
H~nX!sO
//日志 *2->>"kh
public static void log(String sMsg) e4SS'0|
{ T+@i;M
System.err.println(sMsg); A1-,b.Ni
} ZxSFElDD]E
BJWlx*U]
a;Y:UwD9*
public static void log(int sMsg) t^"8M6BqC;
{ 9QXsbd6
System.err.println(sMsg); #jg-q|nd
} X+N5iT
} IRx%L?
$V!.z%Vgf
D^6iQW+.P
/* <3BGW?=WP
**TestMethod.java %p )"_q!ge
*/ # euG$(
package NetFox; M.t,o\xl
'Xj^cX
lWj*tnnn[
public class TestMethod { J.R\h!
TS9<uRO0
[BD`h
public TestMethod() F&R*njJcc
{ ///xx/weblogic60b2_win.exe 7WS$fUBi
try{ @ewaj!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); trwQ@7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Slg*[r#
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2K};-}eW
fileFetch.start(); c86KDEF
} }i"[5:
catch(Exception e){e.printStackTrace ();} p4f9v:b[
4bA^Gq
j}//e%$a
} %AA&n*m
Dh2Cj-| ~
l$\2|D
public static void main(String[] args) 4!!PrXE
{ igA?E56?
new TestMethod(); 9h\RXVk{tA
} !;|#=A9
} ["Ts7;q9[
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